Fabrication of Elemental Copper by Intense Pulsed Light Processing of a Copper Nitrate Hydroxide Ink

Printed electronics and renewable energy technologies have shown a growing demand for scalable copper and copper precursor inks. An alternative copper precursor ink of copper nitrate hydroxide, Cu-2(OH)(3)NO3, was aqueously synthesized under ambient conditions with copper nitrate and potassium hydroxide reagents. Films were deposited by screen-printing and subsequently processed with intense pulsed light. The Cu-2(OH)(3)NO3 quickly transformed in less than 100 s using 40 (2 ms, 12.8 J cm(-2)) pulses into CuO. At higher energy densities, the sintering improved the bulk film quality. The direct formation of Cu from the Cu-2(OH)(3)NO3 requires a reducing agent; therefore, fructose and glucose were added to the inks. Rather than oxidizing, the thermal decomposition of the sugars led to a reducing environment and direct conversion of the films into elemental copper. The chemical and physical transformations were studied with XRD, SEM, FTIR and UV-vis.